Traveling groups of humans are really mobile ecosystems, as we bring with us a whole collection of species we find useful, and not-so-useful: domestic animals, crop plants, pests, diseases, and parasites. Even if we fumigated our clothes and our vehicles, we’d still bring with us a whole collection of intestinal microbes. If you knew nothing more about humans than this, you could reconstruct our historical movement from the changes we’ve made to the living communities around us.
This is one thesis of a new paper in Proceedings of the Royal Society, which shows that the population genetics of house mice in the British Isles still bear the mark of medieval Viking raids. It’s an extremely simple result: in sites especially subject to regular Viking depredations, the northwestern coasts of Scotland and Ireland, the house mice are more closely related to house mice in Norway than they are to mice from other parts of Britain. It’s not clear whether this is because the Vikings brought the first house mice to these areas, or whether stowaway mice from Norway interbred with an already-established population. House mice were in Britain well before the Vikings came along, but human settlements along the northwestern coasts apparently weren’t established much before the Vikings started raiding them.
The authors propose expanding a survey of mouse genetics in Europe to better document the extent of Viking travel. It’s one more biological tool for archaeologists, reconstructing the past based on what we leave behind.
Reference
J.B. Searle, C.S. Jones, İ. Gündüz, M. Scascitelli, E.P. Jones, J.S. Herman, R.V. Rambau, L.R. Noble, R.J. Berry, M.D. Giménez, F. Jóhannesdóttir (2009). Of mice and (Viking?) men: phylogeography of British and Irish house mice. Proc. R. Soc. B, 276 (1655), 201-7 DOI: 10.1098/rspb.2008.0958